The climatic action in Dewey Lambdin’s Alan Lewrie novel, The Captain’s Vengeance, takes place on Grand Terre Island.
Grand Terre, at the top of the above image (for orientation Barataria Bay is to the left and the Gulf of Mexico to the right), was a longtime haunt of pirates and privateersmen. Barataria Bay was virtually impossible to find unless you were looking for it.
Jean Lafitte, who has a cameo role in Lambdin’s novel, used Grand Terre as his base of operations until about 1814 when the US Navy became concerned with protecting commerce to its newly acquired Gulf ports. By 1815 the fact that New Orleans was under military government made Grand Terre and Barataria Bay unsuitable for pirates. Many of them decamped to Cuba and to Galveston, TX.